Two couples rooted in the American mainstream. Two spouses who were nearly killed by mentally ill gunmen.

The comparisons are striking.

Jim and Sarah Brady were loyal Republicans entrenched in Washington politics: she, the daughter of an FBI agent, and he, a Midwestern Eagle Scout. As Ronald Reagan's press secretary, Jim Brady took a bullet from a would-be presidential assassin, leaving him with a debilitating head wound.

Mark Kelly and Gabrielle Giffords could be considered the ultimate Washington power couple of the 21st century.She's a former red-state Democratic congresswoman, a gun owner and a defender of the Second Amendment. Her ex-astronaut husband is a combat war veteran and the son of retired police officers.

It's been two years since a gunman shot Giffords in the head and killed six others outside an Arizona grocery store in what police called an attempted assassination.

The Bradys have spent almost three decades battling America's powerful gun lobby, eventually winning passage of laws requiring background checks for some firearms and bans on some military-style weapons.

President Clinton and Al Gore congratulate Jim and Sarah Brady on the passage of the Brady Law in 1993.

Virtually unknown on a national level until the Tucson shooting in January 2011, Giffords became a household name after her remarkable recovery from a gunshot wound to the head. That fame provides a bright spotlight for her new crusade.

Accusing political leaders of being afraid and of doing nothing, they've formed a political action committee against what they call an "ideological fringe" that uses "big money" to "cow Congress into submission."

Just as the Bradys blazed a trail for the nation's gun control movement, Giffords and her husband are poised to be the next wave.

Outrage and sorrow from Newtown have made this the most opportune time in more than a decade for the passage of new gun control laws, activists say. "We certainly can't allow ourselves to continue down this road when this happens almost now as a regular occurrence," Kelly told CNN's Piers Morgan in January.

"On issues like assault weapons and high-capacity magazines and universal background checks, we differ with the (National Rifle Association) leadership," Kelly said. "But in fact, I think a lot of our positions on this subject are much in line with the NRA membership."

When Giffords and Kelly testified on Capitol Hill in January, they stirred up a hornet's nest of gun owners who believe that background checks and bans on military-style weapons violate their constitutional rights.

Sarah Brady says Giffords and Kelly are the right people for the task.

"You kind of need a public face -- and public faces certainly help," said Brady, longtime leader of the Brady Center to Prevent Gun Violence. "But the most important thing is a really committed, wonderful team, and that's what we had during those battles."

'No-nonsense people'

Pam Simon remembers the day Giffords first became a victim of gun violence. She remembers it well because she herself was among the victims, suffering wounds to her chest and hand. Simon was also there the day her longtime friend decided to take a stand on the issue.

Simon stopped by Giffords' Tucson home the day of the Newtown massacre, greeting her and then asking delicately, "Have you heard the news?"

Giffords and Kelly last week in Tucson. The couple met in 2003 and married three years later.

" 'Awful,' " she recalled Giffords responding, overcome by the weight of the tragedy.

Just a few months earlier, Simon had said to Giffords, "Your job is to inspire people, on a whole variety of issues." Now, she thought, the task at hand couldn't be clearer.

Giffords' toughness and tenacity, said Simon, would be effective tools to keep firearms out of the wrong hands.

"Mark and Gabby are both no-nonsense people," Simon said. "If there's a problem, they get it done. Gabby has always had a true moral compass. And Mark, I mean, he's an astronaut. Astronauts see a problem, and they get it fixed."

No doubt about it, Kelly has a unique resume spanning an eye-popping assortment of jobs from ambulance driver to Merchant Marine cadet to combat naval aviator and, finally, to shuttle and space station astronaut.

He's one of twin brothers (his brother, Scott, is also an astronaut) born to police officers in Orange, New Jersey.

"I think going to the public school kind of made me what I am today,"Kelly said during a NASA interview. He filled the time between classes with baseball, swimming, track and football.

Winning a spot at the Merchant Marine Academy, Kelly, now 49, worked on a grain carrier ship as it inched its way across the Pacific. "I thought, 'Boy, this is way too slow,' " he said. "That's when I started thinking about flying airplanes in the Navy."

Years later, after flying the final mission of the space shuttle Endeavour, Kelly said, he realized that his Navy and NASA training had prepared him to help his wife after she was shot.

"I did see, you know, some parallels between what I had to deal with in flying airplanes and flying the space shuttle and what I had to deal with in handling this situation," Kelly told Piers Morgan in 2011. "I would think about these things in the context of, you know, what information do I have ... what kind of decision do I need to make, and do I need to make the decision right now, or can this wait?"

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Giffords, 42, grew up in the same city where her life nearly ended on January 8, 2011. The daughter of a Tucson school board member, she attended Scripps College in California and later Cornell, where she studied regional planning. She entered politics in 2000, winning a seat in Arizona's legislature and later in the U.S. House of Representatives.

Kelly and Giffords met during a 2003 work trip to China. They reconnected again a year later after Kelly -- who had been married with two girls -- divorced his first wife. They started a long-distance relationship between Houston and Tucson, and by 2006, Giffords and Kelly were married.

The Tucson shooting didn't change Giffords' personality; it amplified it, Simon said. Giffords has relied on her resilience, Simon said, to recover from wounds that have left her with a brain injury, partial blindness and a paralyzed right arm. She resigned from Congress a year ago to focus on her recovery.

"Her speaking is really coming along," Simon said.

Kelly has spoken about some of the most personal ways that the Tucson attack has changed him. Until the shooting, he said, he hadn't been a "big believer in faith."

"I thought the world just spins, and the clock just ticks, and things happen for no particular reason," Kelly said.

The media were not invited as Kelly and Giffords met privately with parents whose children had been shot to death by a 20-year-old armed with a military-style weapon and two handguns.

The "first couple that we spoke to, the dad took out his cell phone and showed us a picture of his daughter, and I just about lost it, just by looking at the picture," Kelly told ABC News. "It was just very tough, and it brought back a lot of memories about what that was like for us some two years ago."

"I have a lot of regard for her," said Pat Llodra, a Newtown community leader who also met with Kelly and Giffords. "She was harmed, and she was still willing to put herself out there to make a change."

Simon expects to see and hear a lot more from Giffords. "She and Mark intend to work together as a team," she said.

What Giffords and Kelly share with the Bradys is their movement toward activism through the power of their own personal tragedies.

Brady has held off reaching out to Giffords and Kelly out of respect for their privacy. "I would love to speak to them now and just thank them for stepping up to the plate and wanting to help on this issue."

John Hinckley Jr. shot President Reagan, Jim Brady and two others outside the Washington Hilton Hotel in 1981.

They're both heroes, she said.

"None of us were activists until the shootings happened."

Sarah Brady didn't enter the gun control fray until four years after her husband had been wounded. That's when Jim Brady's injuries and the horror of seeing her 6-year-old son, Scott, accidentally handling a handgun crystallized her mission one night in 1985. "It just hit me like a ton of bricks," she said. "So I asked Jim if he felt comfortable with me speaking out, and he said, 'of course.'"

After that, the Bradys made it their business to be gun control activists.

Despite budgets that were just a fraction of the gun lobby's, the Bradys and their colleagues helped pass federal and state laws, including Maryland's 1988 ban on cheap handguns known as Saturday night specials, 1993's Brady Law requiring background checks on certain kinds of gun purchases and a ban on manufacturing and future sales of some military-style firearms, which lasted from 1994 to 2004.

Three decades after John Hinckley Jr. shot Reagan, Jim Brady and two others outside the Washington Hilton Hotel, Brady, now 72, has had a tough year, his wife said. "He no longer can stand. He has lost his sight, and he is in some pain. But his mind and everything else is perfect."

Lessons learned

The Bradys' victories may offer winning strategy ideas for Giffords and Kelly.

"Far be it for me to give them advice," said Sarah Brady, now 71. But she's found it helpful to "let members of Congress who are straddling the fence know that public opinion is with you. Make it an embarrassment if they don't do the right thing."

The Brady Law has kept deadly firearms out of the hands of more than 2 million people who failed background checks, according to Brady's group.

Giffords and Kelly say they want Congress to expand the law to require background checks for all gun buyers. Brady agrees.

"We can pass something very, very quickly in the area of background checks," Brady said. "But there are a lot of things that could derail it. With so much of the media everywhere and so many things going on all the time, none of us have the attention span we used to have to stay on one subject. If something new happens, then the discussion will move somewhere else. We've got to stay focused and stay on task and do it quickly."

Brady is optimistic that Congress will vote to expand background checks on firearms purchases. "I think it can be done," she said. "Do I think it's going to be done? I'm not sure. It's going to depend on people like Jim and me and Gabby and Mark."